Risk-Cost Integrated Assessment Based Overhaul Strategies for Transformers

Reliable operation of transformers is of significant importance to the entire power system concerned. Therefore, it is necessary to reduce the failure rate of transformers through timely overhaul. Given this background, the optimal overhaul planning problem for transformers is addressed in this work based on risk-cost integrated assessment. First, a linear aging regression model is established employing the Weibull distribution based failure rate model of transformers. The investment and operation costs of transformers are next classified and calculated according to the theory of Life Cycle Cost (LCC). Subsequently, from the perspective of managing risk, the optimal overhaul time under different overhaul frequencies is formulated as an optimization problem and solved by the Particle Swarm Optimization (PSO) algorithm, and economic analysis based on the annual average LCC is carried out. Finally, a case study is conducted to demonstrate the proposed approach.